Tuyển tập các báo cáo nghiên cứu khoa học ngành toán học được đăng trên tạp chí toán học quốc tế đề tài: Performance evaluation of space-time-frequency spreading for MIMO OFDM-CDMA systems | Dahman and Shayan EURASIP Journal on Advances in Signal Processing 2011 2011 139 http content 2011 1 139 o EURASIP Journal on Advances in Signal Processing a SpringerOpen Journal RESEARCH Open Access Performance evaluation of space-time-frequency spreading for MIMO OFDM-CDMA systems Haysam Dahman and Yousef Shayan Abstract In this article we propose a multiple-input-multiple-output orthogonal frequency division multiplexing codedivision multiple-access MIMO OFDM-CDMA scheme. The main objective is to provide extra flexibility in user multiplexing and data rate adaptation that offer higher system throughput and better diversity gains. This is done by spreading on all the signal domains space-time frequency spreading is employed to transmit users signals. The flexibility to spread on all three domains allows us to independently spread users data to maintain increased system throughput and to have higher diversity gains. We derive new accurate approximations for the probability of symbol error and signal-to-interference noise ratio SINR for zero forcing ZF receiver. This study and simulation results show that MIMO OFDM-CDMA is capable of achieving diversity gains significantly larger than that of the conventional 2-D CDMA OFDM and MIMO MC CDMA schemes. Keywords code-division multiple-access CDMA diversity space-time-frequency spreading multiple-input multiple-output MIMO systems orthogonal frequency-division multiplexing OFDM 4th generation 4G 1. Introduction Modern broadband wireless systems must support multimedia services of a wide range of data rates with reasonable complexity flexible multi-rate adaptation and efficient multi-user multiplexing and detection. Broadband access has been evolving through the years starting from 3G and High-Speed Downlink Packet Access HSDPA to Evolved High Speed Packet Access HSPA 1 and Long Term Evolution LTE . These are examples of next generation systems that provide higher performance data transmission
